From owner-freebsd-doc Fri Aug 24 17:10:10 2001 Delivered-To: freebsd-doc@freebsd.org Received: from freefall.freebsd.org (freefall.freebsd.org [216.136.204.21]) by hub.freebsd.org (Postfix) with ESMTP id A84D637B411 for ; Fri, 24 Aug 2001 17:10:00 -0700 (PDT) (envelope-from gnats@FreeBSD.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.11.4/8.11.4) id f7P0A0549520; Fri, 24 Aug 2001 17:10:00 -0700 (PDT) (envelope-from gnats) Received: from guru.mired.org (okc-94-248-46.mmcable.com [24.94.248.46]) by hub.freebsd.org (Postfix) with SMTP id 71BE437B407 for ; Fri, 24 Aug 2001 17:07:45 -0700 (PDT) (envelope-from mwm@mired.org) Received: (qmail 55403 invoked by uid 100); 25 Aug 2001 00:07:44 -0000 Message-Id: <20010825000744.55402.qmail@guru.mired.org> Date: 25 Aug 2001 00:07:44 -0000 From: Mike Meyer Reply-To: Mike Meyer To: FreeBSD-gnats-submit@freebsd.org X-Send-Pr-Version: 3.113 Subject: docs/30062: [PATCH] The description of disk, slices and partitions lacks detail Sender: owner-freebsd-doc@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org >Number: 30062 >Category: docs >Synopsis: [PATCH] The description of disk, slices and partitions lacks detail >Confidential: no >Severity: non-critical >Priority: medium >Responsible: freebsd-doc >State: open >Quarter: >Keywords: >Date-Required: >Class: doc-bug >Submitter-Id: current-users >Arrival-Date: Fri Aug 24 17:10:00 PDT 2001 >Closed-Date: >Last-Modified: >Originator: Mike Meyer >Release: FreeBSD 4.4-RC i386 >Organization: Meyer Consulting >Environment: System: FreeBSD guru.mired.org 4.4-RC FreeBSD 4.4-RC #4: Sun Aug 19 11:29:30 CDT 2001 mwm@guru.mired.org:/sharetmp/obj/usr/src/sys/GURU i386 >Description: The description of disk, slices and partitions doesn't provide any detail. In particular, there are no examples, nor does it say where in the device name the partition letter windsd up. I don't believe the slice numbering for extension slices are detailed anywhere. >How-To-Repeat: Well, I noticed that there is lots of confusion about slice/partition names on -questions, and on checking the handbook noticed that this wasn't really addressed anywhere. >Fix: The following patch adds the missing information. It also notes that drive numbers start at 0, and that USB mass storage devices are "da" devices. --- chapter.sgml-orig Fri Aug 24 18:29:16 2001 +++ chapter.sgml Fri Aug 24 18:58:22 2001 @@ -177,7 +177,7 @@ wcd before 4.0-RELEASE. - SCSI hard drives + SCSI hard drives and USB Mass storage devices da from 3.0-RELEASE, sd before 3.0-RELEASE. @@ -223,6 +223,11 @@ + All the drives attached through a specific driver are + numbered starting at 0. So the first IDE drive would be + ad0. You seldom need to use + these devices. + Slices and Partitions slices @@ -231,17 +236,31 @@ Physical disks usually contain slices, unless they are dangerously dedicated. Slice numbers follow - the device name, prefixed with an s: - da0s1. + the device name, prefixed with an s, + starting at 1. So da0s1 + is the first slice on the first SCSI drive. There can only be + four physical slices on a disk, but you can have logical + slices inside physical slices of the appropriate type. These + extended slices are numbered starting at 5, so + ad0s5 is the first + extended slice on a disk. These devices are used by file + systems that expect to occupy a slice. Slices, dangerously dedicated physical drives, and other drives contain partitions, which are represented as letters from a to h. - b is reserved for swap partitions, and - c is an unused partition the size of the - entire slice or drive. This is explained in . + This letter is appended to the device name, so + da0a is the a partition on + the first da drive, which is dangerously dedicated. + ad1s3e is the fifth partition + in the third slice of the second IDE disk drive. + + The boot code expects partition a to be + the root partition. Partition b is normally + reserved for swap partitions, and c is an + unused partition the size of the entire slice or drive. This + is explained in . >Release-Note: >Audit-Trail: >Unformatted: To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-doc" in the body of the message